Seal device

ABSTRACT

A seal device has a base member and an elastic member. The elastic member adheres to the base member so as to cover substantially the entire surface of the base member without any adhesive material. Thereby, the elastic member and the base member can be easily removed from each other.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a seal device and more particularly to a lip seal for sealing a gap around a drive shaft of a compressor for use in an air conditioner and a gasket for sealing a joint between housing members Japanese Unexamined Utility Model publication No.5-30637 discloses one of seal devices. The seal device has a base member, or a housing of an oil seal, and an elastic member, or a lip seal made of rubber. The base member is made of a metal plate. The end of the elastic member is fixed to the base member with a reinforcement member and another seal member made of synthetic resin by caulking or by bending the part of base member.

[0002] Since the elastic member is pliant and easily deforms, generally the end of the elastic member fixedly adheres to the base member by means of an adhesive material.

[0003] An unwanted effect is that detaching the elastic member from the base member is difficult since the elastic member adheres to the base member. Also, when the elastic member is detached from the base member with a relatively large force, the part of elastic member remains on the base member. Consequently, recycling the base member is difficult. Therefore, it is desired that the elastic member is easily removed from the base member and the seal device is easily recycled.

SUMMARY OF THE INVENTION

[0004] In accordance with the present invention, a seal device has a base member and an elastic member. The elastic member adheres to the base member so as to cover substantially the entire surface of the base member without any adhesive material.

[0005] Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The features of the present invention that are believed to be novel are set forth with particularity in the appended claims. The invention together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:

[0007]FIG. 1 is a partially schematic view of a lip seal according to a first embodiment of the present invention;

[0008]FIG. 2 is a partially schematic view of a lip seal according to a second embodiment of the present invention;

[0009]FIG. 3A is a partially cross-sectional view of an annular base according to another embodiment of the present invention;

[0010]FIG. 3B is a partially cross-sectional view taken along the line I-I in FIG. 3A;

[0011]FIG. 4A is a partially cross-sectional view of a compressor with a gasket;

[0012]FIG. 4B is a partially enlarged schematic cross-sectional view of the gasket; and

[0013]FIG. 4C is an end view of the gasket.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] A first embodiment of the present invention will now be described with reference to FIG. 1. The front side and the rear side correspond to the left side and the right side in FIG. 1, respectively.

[0015] As shown in FIG. 1, an annular retainer 12, a first seal member 13, a second seal member 14 and a back-up ring 15 constitute a lip seal 11. The retainer 12 or a base member is made of a metal plate. The first seal member 13 or an elastic member is made of rubber. The second seal member 14 is made of synthetic resin. The back-up ring 15 or a reinforcement member is made of a metal plate.

[0016] The first seal member 13 is made of synthetic rubber such as acrylonitrile butadiene rubber, and is annular in shape. Besides, the spring hardness Hs of the synthetic rubber is preferably 75 or above based on stability of shape, and is more preferably 80 or above, and is much more preferably 85 or above. Also, the second seal member 14 is made of fluororesin such as polytetrafluoroethylene (PTFE), and is annular in shape. Also, the cross section of the back-up ring 15 is substantially L-shaped, and the back-up ring 15 is constituted of a cylindrical portion 15A and an extended portion 15B, which extends from the rear end of the cylindrical portion 15A toward the central axis of the lip seal 11.

[0017] The cross section of the retainer 12 is substantially U-shaped. The retainer 12 includes a cylindrical portion 12A, an annular front extended portion 12B and an annular rear extended portion 12C. The cylindrical portion 12A includes a cylindrical surface along the direction of the central axis of the retainer 12. The front extended portion 12B and the rear extended portion 12C respectively extend from the front end of the cylindrical portion 12A and the rear end of the cylindrical portion 12A toward the central axis of the retainer 12.

[0018] Substantially the entire surface of the retainer 12 is formed within the first seal member 13 by insert mold. Strictly, in the retainer 12, the entire surface of the cylindrical portion 12A, the entire surface of the rear extended portion 12C and the front end of the front extended portion 12B are covered with the elastic member, which constitutes the first seal member 13. The first seal member 13 adheres to the retainer 12 without any adhesive material.

[0019] A plurality of through holes 12D is formed to extend through the retainer 12 in thickness. The elastic member, which constitutes the first seal member 13, occupies the through holes 12D, and the elastic member on each side of the retainer 12 interconnects through the through holes 12D.

[0020] The first seal member 13 includes an annular base 13A and an annular lip portion 13B. The base 13A accommodates the retainer 12. The lip portion 13B extends from the base 13A. Parts of outer peripheries of the back-up ring 15 and the second seal member 14 are respectively accommodated in front and rear in a space surrounded by the part of first seal member 13 covering the inner surface (the lower surface in FIG. 1) of the cylindrical portion 12A and the front end surface of the rear extended portion 12C and also by the front extended portion 12B of the retainer 12. A protrusion is formed on the front surface of the rear extended portion 12C of the first seal member 13. The second seal member 14 and the back-up ring 15 are fixedly caulked such that the protrusion and the front extended portion 12B sandwich the second seal member 14 and the back-up ring 15. The second seal member 14 and the back-up ring 15 are assembled to the retainer 12 and the first seal member 13 without any adhesive material such that the second seal member 14 and the back-up ring 15 can be disassembled from the retainer 12 and the first seal member 13.

[0021] Substantially the entire rear surface of the extended portion 15B of the back-up ring 15 contacts with the second seal member 14. A sliding surface 14A of the second seal member 14 with respect to a rotary shaft 16 provides a spiral groove 14B, which functions to return lubricant oil to a sealed region A.

[0022] The lip seal 11 is installed to a compressor such that a protrusion formed on the base 13A abuts against the inner surface of a seal chamber 18, which is defined in a housing 17 of the compressor. Also, the lip seal 11 is supported by the housing 17, and is assembled to the compressor such that the end of the lip portion 13B of the first seal member 13 and the sliding surface 14A of the second seal member 14 abut against the outer circumferential surface of the rotary shaft 16, which is inserted through the seal members 13, 14.

[0023] Additionally, the protrusions respectively formed on the outer periphery of the base 13A and on the first seal member 13 covering the front surface of the rear extended portion 12C ensure relatively high sealing performance. Therefore, no elastic member is interposed between the front end of the cylindrical portion 15A and the rear surface of the front extended portion 12B. Nevertheless, sealing performance of the lip seal 11 is not deteriorated.

[0024] The following advantageous effects are obtained from the present embodiment.

[0025] (1) The first seal member 13 adheres to substantially the entire surface of the retainer 12 without any adhesive material. Thereby, the first seal member 13 is easily removed from the retainer 12. Therefore, the first seal member 13 and the retainer 12 are easily recycled.

[0026] (2) The retainer 12 is made of metal plate. Therefore, relatively high heat-resistance of the base member is easily ensured. For example, the retainer 12 made of metal plate is inhibited from deforming under conditions of relatively high temperature, as compared with the retainer 12 made of resin. Thereby, the retainer 12 made of metal plate tends to be utilized under conditions of relatively high temperature. In addition, in view of gas permeation performance, the retainer 12 made of metal is more efficient than that made of resin.

[0027] (3) The first seal member 13 is formed by insert mold. Thereby, the lip seal 11 is easily mass-produced. Namely, manufacturing cost is reduced.

[0028] (4) The retainer 12 forms the plurality of through holes 12D, which extends in thickness, and the first seal member 13 formed on each side of the retainer 12 interconnects through the through holes 12D. Thereby, the first seal member 13 is inhibited from being removed.

[0029] (5) A space between the outer periphery of the retainer 12 and the wall surface of the seal chamber 18 is sealed by the part of base 13A of the first seal member 13. Thereby, no another seal member such as O-ring requires to be arranged to seal the space. Therefore, the number of parts is reduced, as compared with a structure including such another seal member arranged to seal the space between the outer periphery of the retainer 12 and the wall surface of the seal chamber 18.

[0030] A second embodiment of the present invention will now be described with reference to FIG. 2. The front side and the rear side correspond to the left side and the right side in FIG. 2, respectively. The structure of the lip seal in the first embodiment is modified in the second embodiment. The structure other than the lip seal is similar to that in the first embodiment. Therefore, only the structure different from that in the first embodiment will be described. The same reference numerals denote the similar components to those in the first embodiment.

[0031] An annular case 21, a first seal member 22, a second seal member 23 and a back-up ring 24 constitute a lip seal 20. The annular case 21 is made of metal plate. The first seal member 22 or an elastic member is made of rubber. The second seal member 23 is made of resin. The back-up ring 24 or a reinforcement member is made of metal.

[0032] The first seal member 22 is made of synthetic rubber such as acrylonitrile butadiene rubber, and is annular in shape. Also, the second seal member 23 is made of fluororesin such as polytetrafluoroethylene PTFE, and is annular in shape. Also, the back-up ring 24 is annular disk-shaped.

[0033] The cross section of the case 21 is substantially S-shaped. The case 21 includes an outer cylindrical portion 21A or an outermost outside diameter portion, which includes a cylindrical surface along the direction of the central axis of the case 21. An annular front extended portion 21B and an annular rear extended portion 21C respectively extend from the front end and the rear end of the outer cylindrical portion 21A. Also, in the case 21, an annular O-ring case 21D extends frontward from the radially inner end of the front extended portion 21B.

[0034] The parts of outer peripheries of the back-up ring 24, the second seal member 23 and the first seal member 22 are accommodated in order from the front side in a reentrant 21E, which is formed by the outer cylindrical portion 21A, the front and the rear extended portions 21B, 21C. The first and the second seal members 22, 23 and the back-up ring 24 are fixedly caulked such that the front and the rear extended portions 21B, 21C sandwich the first and the second seal members 22, 23 and the back-up ring 24. The first and the second seal members 22, 23 and the back-up ring 24 are assembled to the case 21 without any adhesive material such that the first and the second seal members 22, 23 and the back-up ring 24 can be disassembled from the case 21.

[0035] An annular retainer 25 or a base member made of metal plate is covered with the first seal member 22 by insert mold, and is arranged in the first seal member 22 adjacent to the outer periphery. The part of retainer 25 is arranged to receive force due to caulking.

[0036] A plurality of through holes 25A is formed to extend through the retainer 25 in thickness (the front and the rear direction in FIG. 2). The elastic member constituting the first seal member 22 occupies the through holes 25A. Thereby, the elastic member formed on each side of the retainer 25 interconnects through the through holes 25A. Therefore, the first seal member 22 adheres to the retainer 25 without any adhesive material.

[0037] Additionally, a sliding surface 23A of the second seal member 23 with respect to the rotary shaft 16 forms a spiral groove 23B, which functions to return lubricant oil to the sealed region A.

[0038] An O-ring 26 is fitted in an annular reentrant, which is formed by the front extended portion 21B and the O-ring case 21D. When the lip seal 20 is installed in the seal chamber 18, the O-ring 26 seals a gap between the wall surface of the seal chamber 18 and the outer periphery of the case 21, and the end of the first seal member 22 and the sliding surface 23A of the second seal member 23 close to the outer circumferential surface of the rotary shaft 16. Thereby, a gap around the rotary shaft 16 is sealed.

[0039] In addition to the advantageous effects mentioned in the paragraph (1) to (4) in the first embodiment, the following advantageous effects are obtained.

[0040] (6) The part of retainer 25 is arranged to receive force due to caulking. In such a state, since the elastic member of the first seal member 22 on each side of the retainer 25 is relatively thin, pressure applied to the elastic member of the first seal member 22 by caulking tends to be relatively large. Therefore, sealing performance on the elastic member of the first seal member 22 on each side of the retainer 25 improves.

[0041] The present invention is not limited to the embodiments described above, but may be modified into the following examples.

[0042] In the above-mentioned embodiments, the base member or the retainer 12, 25 forms the through holes 12D, 25A, which extend in thickness. Thereby, the elastic member or the first seal member 13, 22 formed on each side of the base member interconnects through the through holes 12D, 25A. Meanwhile, grooves may be recessed such that the elastic members formed on each side of the base member respectively occupy the grooves, as shown in FIGS. 3A, 3B. As shown in FIG. 3A, a plurality of grooves 41 (only one groove on each side of the base member shown in FIG. 3) in place of the through holes 12D is recessed on each side of a retainer 40. The bottom of each groove 41 is wider than the opening, and the cross section of each groove 41 is substantially rectangular in shape, as shown in FIG. 3B. The grooves 41 continuously extend from the radially inner end of the front extended portion 40A toward the radially inner end of the rear extended portion 40B on the front extended portion 40A and the rear extended portion 40B, respectively. In such a state, even when the elastic member adheres to the surface of the retainer 40 without any adhesive material, the part of elastic member occupies the grooves 41. Thereby, the elastic member is inhibited from being removed from the retainer 40.

[0043] In the above-mentioned embodiments, the base member or the retainer 12, 25 may form the through holes, which extend in thickness, and the grooves, which are occupied by the part of elastic member, on each side of the base member.

[0044] In the above-mentioned embodiments, a through hole 12D, 25A formed through the base member or the retainer 12, 25 may be omitted.

[0045] In the above-mentioned embodiments, the spiral groove 14B, 23B formed on the second seal member may be omitted.

[0046] In the above-mentioned embodiments, the elastic member or the first seal member 13, 22 is formed by insert mold. However, the elastic member may adhere to the base member or the retainer 12, 25 by a process other than insert mold.

[0047] In the above-mentioned embodiments, the base members 12, 25 are made of plate material. However, the base members may be made of material other than the plate material. For example, in the second embodiment, a retainer made of a wire rod, the cross section of which is rectangular or circular in shape, may be utilized in place of the retainer 25 made of metal plate.

[0048] The above-mentioned structure of the seal device may be applied to a gasket. For example, the structure is applied to a gasket 33 of a valve plate assembly 32, which is interposed between a rear housing 31 and a cylinder block 30 in a compressor, as shown in FIG. 4A. As shown in FIG. 4B, the gasket 33 is constituted of a metal plate 34 or a base member and a rubber layer 35 or an elastic member formed on the surface of the metal plate 34. The rubber layer 35 adheres to the metal plate 34 without any adhesive material. A plurality of through holes 34A is formed to extend through the metal plate 34 in thickness, and the rubber layer 35 formed on each side of the metal plate 34 interconnects through the through holes 34A. As shown in FIG. 4C, the gasket 33 forms a plurality of holes 37 so as to correspond to suction ports and discharge ports of a valve plate 36, and also forms a plurality of through holes 38 for bolts. Besides, as shown in FIG. 4B, the thickness of the rubber layer 35 is exaggerated, as compared with an actual thickness. According to the structure described above, the rubber layer 35 adheres to the metal plate 34 such that the rubber layer 35 can be easily removed from the metal plate 34.

[0049] In the embodiments mentioned above, the base members 12, 25, 34 are made of metal. However, the base members may be made of material other than metal. For example, the base members may be made of resin or fiberglass reinforced plastic (FRP).

[0050] Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein but may be modified within the scope of the appended claims. 

What is claimed is:
 1. A seal device comprising: a base member; and an elastic member adhering to the base member so as to cover substantially the entire surface of the base member without any adhesive material.
 2. The seal device according to claim 1, wherein the base member is made of metal.
 3. The seal device according to claim 1, wherein at least the part of base member is arranged to receive force due to caulking the elastic member.
 4. The seal device according to claim 1, wherein the base member is made of one of resin and fiberglass reinforced plastic.
 5. The seal device according to claim 1, wherein the base member is annular in shape.
 6. The seal device according to claim 1, wherein each side of the base member is recessed to form a groove, and the part of elastic member occupies the groove.
 7. The seal device according to claim 6, wherein the bottom of the groove is wider than the opening of the groove.
 8. The seal device according to claim 6, wherein the groove continuously extends from one end to the other end on each side of the base member.
 9. The seal device according to claim 1, wherein the base member forms a through hole, which extends in thickness, and the elastic member formed on each side of the base member interconnects through the through hole.
 10. The seal device according to claim 1, wherein the elastic member is formed by insert mold.
 11. The seal device according to claim 1, wherein the elastic member is made of rubber.
 12. The seal device according to claim 11, wherein the elastic member is made of synthetic rubber such as acrylonitrile butadiene rubber.
 13. The seal device according to claim 1, wherein the seal device is a lip seal.
 14. The seal device according to claim 1, wherein the seal device is a gasket.
 15. A compressor comprising: a housing; a rotary shaft supported by the housing; and a seal device comprising: a base member having through hole, which is formed to extend through the base member in thickness; and an elastic member adhering to the base member so as to cover substantially an entire surface of the base member, wherein the elastic member on each side of the base member interconnects through the through hole.
 16. The compressor according to claim 15, wherein the seal device is interposed between the housing and the rotary shaft.
 17. The compressor according to claim 15, wherein the seal device is accommodated in the housing.
 18. The compressor according to claim 15 further comprising: a cylinder block connected to the housing; wherein the seal device is interposed between the housing and the cylinder block.
 19. The compressor according to claim 15, wherein the seal device is a lip seal.
 20. The compressor according to claim 15, wherein the seal device is a gasket.
 21. A compressor comprising: a housing: a rotary shaft supported by the housing; and a seal device comprising: a base member having grooves, which is recessed on each side of the base member, the bottom of each groove being wider than the opening of the groove; and an elastic member adhering to the base member so as to cover substantially an entire surface of the base member, wherein the part of elastic member on each side of the base member occupies the grooves. 